Abstract

Quantum cascade lasers have ushered in a new era of enhanced capability for chemical sensing. The higher current and voltage demands of these devices over their laser diode counterparts have also ushered in the demand for more capable drive electronics. The current-sensitivity and high frequency response of these devices have continued the desire for low noise, stability, and agility enjoyed by the laser diode community for many years. This article addresses the issue of maintaining these characteristics at the currents and voltages required, and presents example performance of current controllers developed by the author at Pacific Northwest National Laboratory, achieving output currents up to 2 A and compliance voltages of 15 V, with noise levels close to the Johnson noise of the internal resistors, typically a few . Rapid full-depth current modulation up to 100 kHz is also demonstrated.

Received 01 April 2011Accepted 09 May 2011Published online 29 June 2011

Acknowledgments:

The author wishes to thank members of the Optics Team, in particular Bret Cannon, who provided insight and perspective during the development and testing of the current controller technology, and also Rob Stahl whose technical skills have been absolutely indispensable. The author also wishes to acknowledge the work of others at PNNL who have researched and built current controller prototypes for QCLs, including Jim Kelly, Tim Stewart, and Tom Kiefer. PNNL is operated for the U.S. Department of Energy (DOE) by the Battelle Memorial Institute under Contract No. DE-AC06-76RLO 1830. Part of this work at PNNL was supported by the DOE office of non-proliferation, NA-22.